Computer designers over the past few decades have made extraordinary progress in miniaturizing computers. Electronic devices that once occupied rooms now can comfortably fit on the lap, or in the palm, of a user. An aspect of computers that has not changed quite so much is their cost. Small computers, particularly high performance notebook computers with large screens, are still quite expensive, and their value extends beyond the replacement cost of the computer to include data, lost productivity and reconstruction time.
The small size of notebook computers means that they can be carried by a person on business trips as a productivity enhancement tool. The natural result is that small and expensive notebook computers are often carried into public places, like airports and hotel lobbies, where the opportunity for theft is great. Also notebook computers often are left unattended in less public, but still relatively insecure, places such as offices, conference rooms, and hotel rooms.
The need to prevent theft of personal valuables extends beyond notebook computers to include theft prevention of other portable valuables such as palmtop computers, desktop computer monitors, keyboards and CPUs, personal stereos, music tape and CD players, and roller blades and other personal sporting equipment.
Theft prevention devices have been known in the art. One such scheme employs a security slot fabricated in the notebook computer into which a locking mechanism may be fitted. Typically, a cable is attached permanently or releasably to the locking mechanism. In operation, one end of the cable of the locking mechanism is looped around a chair arm, or some other large, relatively immoveable object, and then passed through a small closed loop in the other end of the cable. The cable is attached to the locking mechanism, if not already attached, and the locking mechanism is then locked to the security slot of the notebook computer. This arrangement prevents or deters theft of the notebook computer as it cannot be freed by passing it through the small cable loop when the locking mechanism is secured to the notebook computer.
Locking mechanisms for securing portable valuables are disclosed, for example, in U.S. Pat. Nos. 5,327,752, 5,493,878 and 5,502,989. Most of the locking mechanisms disclosed in these patents operate in a similar manner. They have a T-shaped crossing member at the distal end of a spindle which is inserted into the security slot, and then rotated. When rotated, the extensions of the T-shaped spindle engage against the inner surface of the wall surrounding the security slot thereby preventing removal of the locking mechanism from the personal, portable valuable.
One limitation of these devices is that the size of the extensions of the shank of the T-shaped spindle must be less than the longest dimension of the security slot so that they may be inserted into the security slot, and the diameter of the spindle must be less than the narrowest dimension of the security slot so that the spindle can rotate in the security slot. This results in relatively little surface contact between the extensions of the shank with the inner surface of the wall surrounding the security slot, and a relatively thin spindle. When forcibly tampered with, the inner wall of the portable valuable is subject to breaking due to large forces being spread over only a relatively small surface area. The spindle, because it has a relatively small diameter, is also subject to breaking during tampering.
The problems with these types of locking mechanisms are further compounded by the fact that in order to accommodate a variety of security slot depths, the length of the spindle exposed beyond the locking mechanism's housing to the cross member is often longer than the depth of the security slot. As a result a gap exits between the outer surface of the wall of the portable valuable and the facing surface of the locking mechanism housing. This gap provides ready access for insertion of, and leverage for, a tool to pry the locking mechanism from the portable device by breaking either the wall surrounding the security slot or the thin spindle.
Another drawback to these types of locking mechanisms is the T-shaped spindle must be inserted and withdrawn from the security slot each time the personal valuable is to be secured or moved. Due to the diminutive size of security slots, this is not always an easy task. Further, over time the repeated insertion and withdrawal of the spindle may cause abrasion and chipping of the sides of the security slot, leading to its enlargement.
Further, both the insertion and locking of these types of locking mechanisms, as well as their unlocking and withdrawal, require the use of a key. Requiring a key to insert and lock the locking mechanism can be an annoying inconvenience to the user, leading to times where the user can not be bothered to securely lock the portable valuable in place.
Thus it is desired to have a locking mechanism that has an extension member that has a larger surface area for engaging a larger surface area of the inner surface of the wall surrounding the security slot of the notebook computer and a thicker spindle or shank not limited in diameter or dimensions to the smallest dimension of the security slot, thereby increasing the strength and durability of the locking mechanism, and making the locking mechanism more theft-resistant.
It is also desired to have a locking mechanism that fits close to the external surface of a wide variety of personal, portable valuables so as to deter their being forcibly pried from the portable valuable.
Further desired is a locking mechanism for portable valuables that can be locked without a key.